<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title></title>
<style>
.red {
	color: #ff0000;
}

.blue {
	color: #0000FF;
}

.gree {
	color: #00FF00;
}

p {
	border: 1px #ff0000 solid;
	padding: 10px;
}
</style>
<script type="text/javascript"
	src="http://ajax.googleapis.com/ajax/libs/ext-core/3.1.0/ext-core.js"></script>
<script>
	Ext.onReady(function() {
		Ext.fly("div_1").radioClass("red");
	});
</script>
</head>

<body>
	<div id="div_1">
		data1
		<p id="p_1">data2</p>
	</div>
	<div id="div_2" class="red">
		data3
		<p id="p_2">data4</p>
	</div>
</body>
</html>